Respirator



Dec. 26, 1961 J. N. MATHESON RESPIRATOR Filed May 20, 1959 INVENTOR. JAM ES N. MATH ESON FIG.4

ATTO R N EYS RESPIRATOR James N. Matheson, Warwick, RJJ, assignor to Welsh :ilanufacturing Company, a corporation of Rhode land Filed May 20, 1959, Ser. No. 814,484 Claims. (Cl. 128-446).

This invention relates to a respiratorof the type to cover the nose and mouth of a person and providean-air seal by the pressure of the edges of'the respirator against the cheeks under the mouth and above the nose of the wearer. v

' One of the problems which has been existent in respirators of this general type is that of providing-an effective seal of a removable filter medium where it engages the body of the respirator. I

Another object of the invention is to provide an effec tive seal of the filter medium and yet provide for interchange of the filter medium so that a filter which has collected a predetermined amount of solid particles may be removed and discarded from the respirator and a fresh, unused filter put in place.

Another object of the invention is to provide for a simple construction by which the parts may be separated for removal of the filter and may be again assembled with the fresh filter in place without undue complexity.

Another'. object of the invention is to provide the parts for locking the filter in place as integral with two portions of the respirator which may be snapped together for assemblyl I Another object of the invention'is to provide a respira tor which will expose a maximum area of the filter medium for operation in the respirator.

Another object of the invention is to provide a simple and etficient exhalation valve for the respirator.

With these and other objects in View, the invention consists of certain novel features of construction as will be more fully described and particularly pointed out in the appended claims.

In the accompanying drawings:

FIGURE 1 is a perspective view of the respirator showing the same ready for mounting upon the face of the user;

FIGURE 2 is a central sectional view through the respirator;

FIGURE 3 is a plan view of the separate retaining frame for holding the filter in place;

FIGURE 4 is a bottom view of the respirator illustrating the air exhalation valve;

FIGURE 5 is a fragmental sectional view on line 5-5 of FIGURE 4; and

FIGURE 6 is a view similar to FIGURE 4 but showing a slightly modified construction.

In proceeding with this invention, I have provided a body member having a rearwardly extending portion, the edge of which encircles an area of the face including the mouth and nose and contacts therewith in sealed engagement with the face. Extending inwardly from the forward edge of this encircling portion, there is a lip against which the peripheral edge of a filter engages while there is a general framework of material extending diametrically from lip to lip for supporting the filter against movement toward the face. The filter is inserted from the rear of the body against the lip and a separate frame having a peripheral portion corresponding with the shape of the lip is used to force the filter against the lip and be itself retained, while there is some sort of an interlocking or interengaging means between the frame and the body so as to hold the filter compressed at its peripheral edge and provide an effective seal. The lower portion of the body which extends rearwardly beneath the mouth is 3,014,479 Patented Dec. 26, 1961 provided withan exhalation valve of a simple type which and-flexible so that it may be drawn against the face to may. be easily inserted or removed from the body. Thus; essentially I provide a body into which a filter may be inserted and retained by a separate frame inserted in the body following the filter, while also the exhalation valve maylbe easily inserted in place or removed for replacement; v

With 'eference to the drawings, 10 designates generally the respirator body which has a flange 11 extending rearwardly'in 'a size to encircle the nose and mouth of the user. The edge 12 of this flange is irregularly shaped engage the cheeks, a portion of the face below the lower lip of the mouth, and the nasal portion about the nose adjacent the eyes. The flexibility of the edge and its general shape enable the body of the respirator to be drawn tightly against the face by elastic straps 13 and generally open as at 17 and about the peripheral edge of this opening and extending inwardly from the flange 11,

there is a lipj'18 which encircles this opening and extends from the flange inwardly a short distance possibly a quarter of an inch and provides a seat against which a sheet-like filter material or medium may be placed.

The filter medium is designated generally 19 and comprises a suitablesynthetic spongy sheet which is capable of're'moving a high, percentage of contaminant from the air which may be drawn therethrough for breathing. Various filter mediums may be provided depending upon the contaminant to be removed, but in general the filter mediums will be in sheet-like form and substantially an eighth of an inch thick. They will be shaped substantially the shape of the interior of the flange 1*1 so as to overlie the inner surface of the lip 18 and rest thereagainst. In order to support the filter on its outer surface across the openings 17 inwardly of the lip 18, I have provided a framework designated generally 20 which comprises bars 21 and 22 extending diametrically, vertically and horizontally across the opening 17 with some design shape worked into the center of the bars. Extending rearwardly from these bars there are projections 23 which engage the filter 19 and maintain it spaced from the bars, although in a supporting relation with reference thereto.

In order to retain the filter in this position, I have pro vided a separate frame 25 shown by itself in FIGURE 3 which comprises an outer peripheral margin 26 of a shape corresponding to the shape of the lip 18 and of a width substantially the same as the width of the lip 18, while bars 27 and 28 extend diametrically, horizontally and vertically across from margin to margin and leave open spaces 29 between the bars and the margin. Likewise, there is a design portion in the center of this frame which corresponds to the design of the frame 20. This separate frame 25 follows in back of the filter 19 and is positioned from the rear of the respirator so that its marginal edge 26 engages the filter and when pressure is applied, forces it so as to be in compressed relation to about one-half its thickness, squeezing the filter between the lip 18 and this marginal edge 26. The separate frame 25 as it is forced inwardly snaps beyond the abutting surface 30 of lugs 31 which extend inwardly from the flange 11 at intervals, there being three along the side flange and two along the bottom flange of the respirator. These lugs 31 taper down into smooth relation with the flange 1 1 and as the separate frame is forced inwardly, it is flexed until it snaps past the abutment edge 30 of each of these lugs when it then straightens out and holds the filter in a compressed relation at its peripheral edge so as to seal it against the passage of air at this location. This separate frame 25 is also provided with projections 32 extending forwardly from the bars 27 so as to engage flange, and an open frame 'cally from lip tolip and secured thereto, a filter shaped the filter and space it' from these bars; 'thus" affording a maximum surface of the filter for passage of air and collection of contaminant. It will also be noted that the projeti ns'az' ares'tagger'ed with relation to the pro} 1 the notches 46"securin'g the strap-s6 that it will be held by this str'a'p' at its center and pretrehted from endwi'se'or si'de'wi'se movement while one portion 41 will cover one of the' openings' and another portion 42 will cover another of the opehings'so that as air is" inhaled, the pressure" within the respirator will be reduced and air will pass throngh'the' filterand' draw the valves closed, 'but 'a's'it' is exhalqd, the alvel will 'be of such flexibility that it will be of"less'resista'nc e to't'he passage of air outwardly than is the filter so" tliaf the will pass out through the openings 36 as the flaps? and 42 o en and thus reduce the exhalation efiortnecessary. 'In some cases instead of having a' generally rectangular shape wlalv'e as at 40, the valve 43 be provided with openings as at 44 at either side'an'd ton'giies' 45 raised from the stock of the flange 35 willpas's through these openings ando've'rlie' a portion of the alye' 43. The actiojn would'be the same; the retaining ineahs being slightly diflfrht. I."='A"re'spirator to cover the nose and rnouth comprising a'body member haying'a r'earvjiardly extendingen ci'r'cling flange; the rear edge of which is for engaging the face o'ha've sealing engagemen't'therewith, a" periph- 'a i jeen zns ifih i t m 'f e a s frame'has' openings registering with the opea'fra extending generally diametrito conform to the interior shape of said flange engaging on its front side said lip and open frame, a separate radially non-collapsible retaining frame also shaped to conform to the interior of said" ilange"wi th a peripheral marbin of a shape and siie substaiitially like said lip, and s ha n bii ich l i e s with st es lea in thereto carried by the interior of said flange back ofnwltieh said separate fran'ie -r'riay be forced"alongsaid taper to lock the separate frame against said filter and seal it at its periphery to said body. I a

2. Krspiratofas'in'clairn 1 wherein said sep' the body and supports the filter between'sa id'frames; "3; A respirator as in claim lwherein 's'aid bfi'dy'and flange is more flexible than said separate frame to flex as 'saidseparate frame is forced into sealing position i 4. A' respirator as in" claim 1 wherein said separate.

Re erees? We! h fi e sf is P39 UNITED STATES PATENTS 

